DNA extraction buffer and method of use thereof

ABSTRACT

Internal Transcribed Spacer (ITS) DNA sequences from the ribosomal RNA gene region are described for different species and strains of Helminthosporium carbonum, Helminthosporium turcicum, Helminthosporium maydis, Cercospora zeae-maydis, Kabatiella zeae and Puccinia sorghi. Specific primers from within these sequences are identified as being useful for the identification of the fungal isolates using PCR-based techniques. Also described is a novel extraction buffer solution for use in isolating DNA from an organism.

This is a divisional of Ser. No. 08/742,023, filed Nov. 1, 1996 now U.S. Pat. No. 5,800,997.

FIELD OF THE INVENTION

The present invention relates to the use of species-specific primers in polymerase chain reaction assays for the detection of fungal pathogens of maize. The use of these primers enables the detection of specific isolates of fungal pathogens and the monitoring of disease development in plant populations. The present invention also relates to a novel extraction buffer solution for use in isolating DNA from an organism.

BACKGROUND OF THE INVENTION

Diseases in plants cause considerable crop loss from year to year resulting both in economic deprivation to farmers and, in many parts of the world, to shortfalls in the nutritional provision for local populations. The widespread use of fungicides has provided considerable security against plant pathogen attack. However, despite $1 billion worth of expenditure on fungicides, worldwide crop losses amounted to approximately 10% of crop value in 1981 (James, 1981; Seed Sci. & Technol. 9: 679-685).

The severity of the destructive process of disease depends on the aggressiveness of the pathogen and the response of the host. One aim of most plant breeding programs is to increase the resistance of host plants to disease. Typically, different races of pathogens interact with different varieties of the same crop species differentially, and many sources of host resistance only protect against specific pathogen races. Furthermore, some pathogen races show early signs of disease symptoms, but cause little damage to the crop. Jones and Clifford (1983; Cereal Diseases, John Wiley) report that virulent forms of the pathogen are expected to emerge in the pathogen population in response to the introduction of resistance into host cultivars and that it is therefore necessary to monitor pathogen populations. In addition, there are several documented cases of the evolution of fungal strains that are resistant to particular fungicides. As early as 1981, Fletcher and Wolfe (1981; Proc. 1981 Brit. Crop Prot. Conf.) contended that 24% of the powdery mildew populations from spring barley and 53% from winter barley showed considerable variation in response to the fungicide triadimenol and that the distribution of these populations varied between varieties, with the most susceptible variety also giving the highest incidence of less susceptible types. Similar variation in the sensitivity of fungi to fungicides has been documented for wheat mildew (also to triadimenol), Botrytis (to benomyl), Pyrenophora (to organomercury), Pseudocercosporella (to MBC-type fungicides) and Mycosphaerella fijiensis to triazoles to mention just a few (Jones and Clifford; Cereal Diseases, John Wiley, 1983).

The three most important cereal crops in the world are maize (corn), rice and wheat (1973; Compendium of Corn Diseases, Amer. Phytopath. Soc. page 1). There are a great number of fungi, bacteria, and viruses that are pathogenic to maize, causing 9.4 % annual worldwide losses. In the corn belt of the United States, maize reduction because of disease infection is between 7 to 17% annually. Maize is the most important native American plant, and the U.S. produces about 44% of the world's 250 million metric tons annual production.

The major infectious diseases of maize are caused by fungi and include rusts, smuts, downy mildews, rots, spots, blights and deformations (1973; Compendium of Corn Diseases, Amer. Phytopath. Soc. page 13). Although fungal diseases are usually diagnosed by the structures produced by the pathogens, the differential symptomology caused by different isolates and species of these fungi make the accurate predictive determination of potential disease loss difficult. Consequently, the availability of improved diagnostic techniques for the rapid and accurate identification of specific pathogens will be of considerable use to field pathologists.

There are three primary species of Helminthosporium pathogenic to maize causing foliar diseases. Helminthosporium carbonum causes helminthosporium leaf spot (blight), also known as northern leaf spot (1973; Compendium of Corn Diseases, Amer. Phytopath. Soc. page 17). It is distributed throughout the Americas, southeast Asia, southeast Europe, south and central Africa, and India (Jones and Clifford; Cereal Diseases, John Wiley, 1983). There are two primary physiologically-based races. Race 1 is highly virulent on maize, causing a charred appearance on the ear's kernels. Race 2 tends to be less virulent than race 1 and does not diplay host specificity. Race 2 produces a host-specific toxin. Helminthosporium maydis causes southern leaf blight in maize. It occurs worldwide in warm (20-32° C.), humid climates. In the United States, it is found in the southeastern and midwestern states (Jones and Clifford; Cereal Diseases, John Wiley, 1983). The disease was originally thought to be of little economic importance until a severe 1970 epidemic in the U.S. resulted in large losses. Northern leaf blight (turcicum leaf blight) is caused by Helminthosporium turcicum. The disease develops in humid areas of the world where maize is grown (1973; Compendium of Corn Diseases, Amer. Phytopath. Soc. page 16). Moderate temperatures (18-27° C.) and heavy dews during the growing season promote severe disease development in which 50% losses of grain can occur. Typical control of these diseases include the use fungicides, crop rotation, burning crop debris, and breeding resistant hybrids and varieties.

Kabateilla zeae is another significant maize foliar pathogen causing eyespot disease. The disease originally reported as brown eyespot in Japan has also been found in Canada, Argentina, Austria, France, Germany, Yugoslavia, New Zealand and in several north-central U.S. states and Pennsylvania (1973; Compendium of Corn Diseases, Amer. Phytopath. Soc. page 21). The disease may develop on sheaths and outer husks, but lesions are more concentrated on leaves approaching maturity. In extremely infected plants, kernel infections may also develop. Cool, humid weather favors disease development. Disease control measures include the use of less susceptible hybrids, fungicides, and clean plowing or crop rotation.

Cercospora or gray leaf spot is caused by Cercospora zeae-maydisand infects maize, barnyardgrass, Johnsongrass and other Sorghum species (1973; Compendium of Corn Diseases, Amer. Phytopath. Soc. page 24). The disease is prevalent in warm-to-hot, humid areas of the United States, Mexico, Central America, northern South America, Europe, Africa, southeast Asia, India, China, and the Philippines. The disease has increased in severity in recent years in the southeastern and mid-Atlantic states of the U.S. especially in areas using minimum tillage of maize and no crop rotation (Latterell and Rossi, 1983; Plant Disease. Vol. 67, No. 8: 842-847). The disease can spread from the leaf sheaths to the stalk in highly infected plants. This can cause stalk deterioration to the point where lodging precludes mechanical harvesting. Crop rotation, resistant cultivars and fungicides are currently used to control gray leaf spot.

Puccinia sorghi causes common maize rust and can be found wherever maize is grown. Infection can occur on any plant parts above ground but is mainly found on the leaves (1973; Compendium of Corn Diseases, Amer. Phytopath. Soc. page 24). Cooler temperatures (16-23 ° C.) and high moisture contribute to the proliferation of the disease. Under severe infection conditions, chlorosis and death of the leaves and sheaths may occur ultimately reducing cereal yield.

Thus, there is a real need for the development of technology that will allow the identification of specific races of pathogen fungi early in the infection process. By identifying the specific race of a pathogen before disease symptoms become evident in the crop stand, the agriculturist can assess the likely effects of further development of the pathogen in the crop variety in which it has been identified and can choose an appropriate fungicide if such application is deemed necessary.

Additionally, with the increasing need for DNA fingerprinting, restriction fragment length polymorphism (RFLP) analysis, Southern transfers and PCR analysis, the isolation of high molecular weight DNA becomes a major problem when attempting to process a large number of plant samples in a timely manner. Several methods for the isolation of DNA have been reported, all of which have drawbacks for various reasons. These include DNA losses due to degradation and adsorption, the co-isolation of PCR inhibiting contaminants and labor extensive and costly protocols. Therefore, there is a need for a DNA extraction method which isolates high molecular weight DNA for high throughput analysis using molecular biology methods.

SUMMARY OF THE INVENTION

The present invention is drawn to methods of identification of different pathotypes of plant pathogenic fungi. The invention provides Internal Transcribed Spacer (ITS) DNA sequences that show variability between different fungal pathotypes. In a preferred embodiment, the invention provides ITS1 and ITS2 DNA sequences for the pathogens Helminthosporium carbonum, Helminthosporium turcicum, Helminthosporium maydis, Cercospora zeae-maydis, Kabatiella zeae, and Puccinia sorghi. Such DNA sequences are useful in the method of the invention as they can be used to derive primers for use in polymerase chain reaction (PCR)-based diagnostic assays. These primers generate unique fragments in PCR reactions in which the DNA template is provided by specific fungal pathotypes and can thus be used to identify the presence or absence of specific pathotypes in host plant material before the onset of disease symptoms.

This invention provides the possibility of assessing potential damage in a specific crop variety-pathogen strain relationship and of utilizing judiciously the diverse armory of fungicides which is available. Furthermore, the invention can be used to provide detailed information on the development and spread of specific pathogen races over extended geographical areas. The invention provides a method of detection that is especially suitable for diseases with a long latent phase. In addition, a method is described for extracting DNA from plant tissue for high throughput PCR analysis.

Kits useful in the practice of the invention are also provided. The kits find particular use in the identification of the pathogens Helminthosporium carbonum, Helminthosporium turcicum, Helminthosporium maydis, Cercospora zeae-maydis, Kabatiella zeae, and Puccinia sorghi.

BRIEF DESCRIPTION OF THE SEQUENCES IN THE SEQUENCE LISTING

SEQ ID NO:1 DNA sequence of the ITS region from Cercospora zeae-maydisisolate #Ladder 3-1 (clone pCRCZLAD3-1(4-3)), comprising in the 5' to 3' direction: 3' end of small subunit rRNA gene, Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:2 DNA sequence of the ITS region from Cercospora zeae-maydisisolate #POS 12 (clone pCRCZMPOS12(2-1)), comprising in the 5' to 3' direction: 3' end of small subunit rRNA gene, Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:3 DNA sequence of the ITS region from Kabatiella zeae isolate #56351 (clone pCRKZ56351(5-1)), comprising in the 5' to 3' direction: 3' end of small subunit rRNA gene, Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:4 DNA sequence of the ITS region from Helminthosporium maydis isolate #24772 (clone pCRHMAY24772(2-1)), comprising in the 5' to 3' direction: 3' end of small subunit rRNA gene, Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:5 DNA sequence of the ITS region from Helminthosporium maydis isolate #11534 (clone pCRHMAY11534(4-1)), comprising in the 5' to 3' direction: 3' end of small subunit rRNA gene, Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:6 DNA sequence of the ITS region from Helminthosporium turcicum isolate #26306 (clone pCRHTUR26306(3-1)), comprising in the 5' to 3' direction: 3' end of small subunit rRNA gene, Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:7 DNA sequence of the ITS region from Helminthosporium carbonum isolate #16185 (clone CRHCAR16185(5-2)), comprising in the 5' to 3' direction: 3' end of small subunit rRNA gene, Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:8 DNA sequence of the ITS region from Puccinia sorghi (GenBank accession #L08734), comprising in the 5' to 3' direction: partial sequence of Internal Transcribed Spacer 1, 5.8S rRNA gene, Internal Transcribed Spacer 2, and 5' end of large subunit rRNA gene.

SEQ ID NO:9 Oligonucleotide Primer ITS1.

SEQ ID NO:10 Oligonucleotide Primer ITS2.

SEQ ID NO:11 Oligonucleotide Primer ITS3.

SEQ ID NO:12 Oligonucleotide Primer ITS4.

SEQ ID NO:13 M13 Universal-20 Primer.

SEQ ID NO:14 Reverse Primer used in Example 2.

SEQ ID NO:15 Oligonucleotide Primer JB586.

SEQ ID NO:16 Oligonucleotide Primer JB587.

SEQ ID NO:17 Oligonucleotide Primer JB588.

SEQ ID NO:18 Oligonucleotide Primer JB589.

SEQ ID NO:19 Oligonucleotide Primer JB590.

SEQ ID NO:20 Oligonucleotide Primer JB591.

SEQ ID NO:21 Oligonucleotide Primer JB592.

SEQ ID NO:22 Oligonucleotide Primer JB593.

SEQ ID NO:23 Oligonucleotide Primer JB594.

SEQ ID NO:24 Oligonucleotide Primer JB595.

SEQ ID NO:25 Oligonucleotide Primer JB596.

SEQ ID NO:26 Oligonucleotide Primer JB597.

SEQ ID NO:27 Oligonucleotide Primer JB598.

SEQ ID NO:28 Oligonucleotide Primer JB615.

SEQ ID NO:29 Oligonucleotide Primer JB616.

SEQ ID NO:30 Oligonucleotide Primer JB617.

SEQ ID NO:31 Oligonucleotide Primer JB618.

SEQ ID NO:32 Oligonucleotide Primer JB619.

SEQ ID NO:33 Oligonucleotide Primer JB620.

SEQ ID NO:34 Oligonucleotide Primer JB621.

SEQ ID NO:35 Oligonucleotide Primer JB622.

SEQ ID NO:36 Oligonucleotide Primer JB623.

SEQ ID NO:37 Oligonucleotide Primer JB624.

SEQ ID NO:38 Oligonucleotide Primer JB625.

SEQ ID NO:39 Oligonucleotide Primer JB626.

SEQ ID NO:40 Oligonucleotide Primer JB627.

SEQ ID NO:41 Oligonucleotide Primer JB628.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides unique DNA sequences that are useful in identifying different pathotypes of plant pathogenic fungi. Particularly, the DNA sequences can be used as primers in PCR-based analysis for the identification of fungal pathotypes. The DNA sequences of the invention include the Internal Transcribed Spacer (ITS) sequences of the ribosomal RNA gene regions of particular fungal pathogens as well as primers derived from these regions that are capable of identifying the particular pathogen. These ITS DNA sequences from different pathotypes within a pathogen species or genus, which vary between the different members of the species or genus, can be used to identify those specific members.

Biomedical researchers have used PCR-based techniques for some time and with moderate success to detect pathogens in infected animal tissues. Only recently, however, has this technique been applied to detect plant pathogens. The presence of Gaumannomyces graminis in infected wheat has been detected using PCR of sequences specific to the pathogen mitochondrial genome (Schlesser et al., 1991; Applied and Environ. Microbiol. 57: 553-556), and random amplified polymorphic DNA (i.e. RAPD) markers were able to distinguish numerous races of Gremmeniella abietina, the causal agent of scleroderris canker in conifers. More recently, primers from within DNA sequences from the ITS of the ribosomal RNA gene region of strains of Septoria, Pseudocercosporella, Fusarium, and Mycosphaerella have been identified as being useful for the identification of the fungal isolates using PCR-based techniques (WO 95/29260, herein incorporated by reference in its entirety.)

Ribosomal genes are suitable for use as molecular probe targets because of their high copy number. Despite the high conservation between mature rRNA sequences, the non-transcribed and transcribed spacer sequences are usually poorly conserved and are thus suitable as target sequences for the detection of recent evolutionary divergence. Fungal rRNA genes are organized in units, each of which encodes three mature subunits of 18S (small subunit), 5.8S, and 28S (large subunit). These subunits are separated by two Internal Transcribed Spacers, ITS1 and ITS2, of around 300 bp (White et al., 1990; In: PCR Protocols; Eds.: Innes et al.; pages 315-322). In addition, the transcriptional units are separated by non-transcribed spacer sequences (NTSs). The ITS and NTS sequences are particularly suitable for the detection of specific pathotypes of different fungal pathogens.

The DNA sequences of the invention are from the Internal Transcribed Spacer sequences of the ribosomal RNA gene region of different plant pathogens. The ITS DNA sequences from different pathotypes within a pathogen species or genus vary among the different members of the species or genus. Once having determined the ITS sequences of a pathogen, these sequences can be aligned with other ITS sequences. In this manner, primers can be derived from the ITS sequences. That is, primers can be designed based on regions within the ITS sequences that contain the greatest differences in sequence among the fungal pathotypes. These sequences and primers based on these sequences can be used to identify specific pathogens.

Particular DNA sequences of interest include ITS1 and ITS2 DNA sequences from Helminthosporium carbonum, Helminthosporium turcicum, Helminthosporium maydis, Cercospora zeae-maydis, Kabatiella zeae and Puccinia sorghi. Examples of such ITS DNA sequences are disclosed in SEQ ID Nos: 1-8. However, isolates of these organisms other than the isolates described herein may have minor sequence variations in their ITS regions. The present invention is intended to encompass the ITS DNA sequences of any isolates of these fungal pathogens. Sequences of oligonucleotide primers of interest are disclosed in SEQ ID Nos: 9-41. The sequences find use in the PCR-based identification of the pathotypes of interest.

Methods for the use of the primer sequences of the invention in PCR analysis are well known in the art. For example, see U.S. Pat. Nos. 4,683,195 and 4,683,202, as well as Schlesser et al. (1991) Applied and Environ. Microbiol. 57:553-556. See also, Nazar et al. (1991; Physiol. and Molec. Plant Pathol. 39: 1-11), which used PCR amplification to exploit differences in the ITS regions of Verticillium albo-atrum and Verticillium dahliae and therefore distinguish between the two species; and Johanson and Jeger (1993; Mycol. Res. 97: 670-674), who used similar techniques to distinguish the banana pathogens Mycosphaerella fijiensis and Mycospharella musicola.

The ITS DNA sequences of the invention can be cloned from fungal pathogens by methods known in the art. In general, the methods for the isolation of DNA from fungal isolates are known. See, Raeder & Broda (1985) Letters in Applied Microbiology 2:17-20; Lee et al. (1990) Fungal Genetics Newsletter 35:23-24; and Lee and Taylor (1990) In: PCR Protocols: A Guide to Methods and Applications, Innes et al. (Eds.); pages 282-287.

Alternatively, the ITS sequences of interest can be determined by PCR amplification. In an exemplified embodiment, primers to amplify the entire ITS sequence were designed according to White et al. (1990; In: PCR Protocols; Eds.: Innes et al. pages 315-322), and the amplified ITS sequence was subcloned into the pCRII cloning vector. The subcloned sequence included the left hand ITS (ITS1), the right hand ITS (ITS2), as well as the centrally located 5.8S rRNA gene. This was undertaken for Helminthosporium carbonum, Helminthosporium turcicum, Helminthosporium maydis, Cercospora zeae-maydis, and Kabatiella zeae.

The ITS sequences were determined and the sequences were compared within each pathogen group to locate divergences that might be useful to test in PCR to distinguish the different species and/or strains. The ITS DNA sequences that were determined are shown in SEQ ID Nos: 1-7 as well as in FIGS. 1-6. From the identification of divergences, numerous primers were synthesized and tested in PCR-amplification. Templates used for PCR-amplification testing were firstly purified pathogen DNA, and subsequently DNA isolated from infected host plant tissue. Thus, it was possible to identify pairs of primers that were diagnostic, i.e. that identified one particular pathogen species or strain but not another species or strain of the same pathogen.

Preferred primer combinations are able to distinguish between the different species or strains in infected host tissue, i.e. host tissue that has previously been infected with a specific pathogen species or strain. This invention provides numerous primer combinations that fulfill this criterion for different Helminthosporium carbonum, Helminthosporium turcicum, Helminthosporium maydis, Cercospora zeae-maydis, Kabatiella zeae, and Puccinia sorghi. The primers of the invention are designed based on sequence differences among the fungal ITS regions. A minimum of one base pair difference between sequences can permit design of a discriminatory primer. Primer, designed to a specific fungal DNA's ITS region can be used in combination with a primer made to a conserved sequence region within the ribosomal DNA's coding region to amplify species-specific PCR fragments. In general, primers should have a theoretical melting temperature between about 60 to about 70 degree ° C. to achieve good sensitivity and should be void of significant secondary structure and 3' overlaps between primer combinations. Primers are generally at least about 5-10 nucleotide bases long.

The present invention lends itself readily to the preparation of "kits" containing the elements necessary to carry out the process. Such a kit may comprise a carrier being compartmentalized to receive in close confinement therein one or more container, such as tubes or vials. One of the containers may contain unlabeled or detectably labeled DNA primers. The labeled DNA primers may be present in lyophilized form or in an appropriate buffer as necessary. One or more containers may contain one or more enzymes or reagents to be utilized in PCR reactions. These enzymes may be present by themselves or in mixtures, in lyophilized form or in appropriate buffers.

Finally, the kit may contain all of the additional elements necessary to carry out the technique of the invention, such as buffers, extraction reagents, enzymes, pipettes, plates, nucleic acids, nucleoside triphosphates, filter paper, gel materials, transfer materials, autoradiography supplies, and the like.

The examples below show typical experimental protocols that can be used in the isolation of ITS sequences, the selection of suitable primer sequences, the testing of primers for selective and diagnostic efficacy, and the use of such primers for disease and fungal isolate detection. Such examples are provided by way of illustration and not by way of limitation.

EXAMPLES

Standard recombinant DNA and molecular cloning techniques used here are well known in the art and are described by J. Sambrook, E. F. Fritsch and T. Maniatis, Molecular Cloning: A Laboratory manual, Cold Spring Harbor laboratory, Cold Spring Harbor, N.Y. (1989) and by T. J. Silhavy, M. L. Berman, and L. W. Enquist, Experiments with Gene Fusions, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1984) and by Ausubel, F. M. et al., Current Protocols in Miolecular Biology, pub. by Greene Publishing Assoc. and Wiley-Interscience (1987).

Example 1

Fungal Isolates and Genomic Fungal DNA Extraction

See Table 1 for a listing of the fungal isolates used and their source. Fungi except for Puccina sorghi were grown in 150 ml potato dextrose broth inoculated with mycelial fragments from PDA (Potato Dextrose Agar) cultures. Cultures were incubated on an orbital shaker at 28° C. for 7-11 days. Mycelia were pelleted by centrifugation and then ground in liquid nitrogen and total genomic DNA extracted using the protocol of Lee and Taylor (1990; In: PCR Protocols: A Guide to Methods and Applications; Eds.: Innes et al.; pages 282-287). Since P. sorghi is an obligate biotroph and could therefore not be cultured on PDA, DNA was isolated from its spores from an infected maize leaf and ground with a Kontes pestle.

                  TABLE 1                                                          ______________________________________                                         Source of Test Isolates                                                        Fungus       Isolate   Origin      Source                                      ______________________________________                                         Helminthosporium                                                                            6921      Illinois    C. Naidoo.sup.2                             maydis.sup.1                                                                   Helminthosporium                                                                            XXXX      Illinois    C. Naidoo                                   maydis                                                                         Helminthosporium                                                                            5654      Illinois    C. Naidoo                                   maydis                                                                         Helminthosporium                                                                            11534     Maryland    ATCC.sup.3                                  maydis                                                                         Helminthosporium                                                                            4709      Indiana     C. Naidoo                                   maydis                                                                         Helminthosporium                                                                            24772     North Carolina                                                                             ATCC.sup.3                                  maydis, Race t,                                                                mating type A                                                                  Helminthosporium                                                                            6810      Iowa        C. Naidoo                                   turcicum.sup.4                                                                 Helminthosporium                                                                            6830      Minnesota   C. Naidoo                                   turcicum                                                                       Helminthosporium                                                                            6402      Illinois    C. Naidoo                                   turcicum, Race 2                                                               Helminthosporium                                                                            6870      Texas       C. Naidoo                                   turcicum                                                                       Helminthosporium                                                                            6586      Illinois    C. Naidoo                                   turcicum, Race 1                                                               Helminthosporium                                                                            26306     Illinois    ATCC                                        turcicum                                                                       Helminthosporium                                                                            6294      Indiana     C. Naidoo                                   turcicum, Race 2                                                               Helminthosporium                                                                            5352      Ohio        C. Naidoo                                   turcicum, Race 2                                                               Helminthosporium                                                                            5870      Illinois    C. Naidoo                                   carbonum.sup.5                                                                 Helminthosporium                                                                            6164      Iowa        C. Naidoo                                   carbonum                                                                       Helminthosporium                                                                            6330      Nebraska    C. Naidoo                                   carbonum                                                                       Helminthosporium                                                                            6378      Iowa        C. Naidoo                                   carbonum                                                                       Helminthosporium                                                                            16185     Virginia    ATCC                                        carbonum                                                                       Kabatiella zeae                                                                             18594     Wisconsin   ATCC                                        Kabatiella zeae                                                                             5125      Indiana     C. Naidoo                                   Kabatiella zeae                                                                             56344     Wisconsin   ATCC                                        Kabatiella zeae                                                                             56351     Michigan    ATCC                                        Kabatiella zeae                                                                             6823      Minnesota   C. Naidoo                                   Cercospora zeae-maydis                                                                      5860      Illinois    C. Naidoo                                   Cercospora zeae-maydis                                                                      6939      Ohio        C. Naidoo                                   Cercospora zeae-maydis                                                                      6911      Illinois    C. Naidoo                                   Cercospora zeae-maydis                                                                      6928      Illinois    C. Naidoo                                   Cercospora zeae-maydis                                                                      SKIN11    Indiana     L. Dunkle.sup.6                             Cercospora zeae-maydis                                                                      Ladder 3-1                                                                               Indiana     L. Dunkle                                   Cercospora zeae-maydis                                                                      POS12     Indiana     L. Dunkle                                   Macrophomina 103       Kansas      J. Mihail.sup.7                             phaseolina                                                                     Macrophomina 97        St. Charles, MO                                                                            J. Mihail                                   phaseolina                                                                     Aspergillus flavus                                                                          NRRL3557  --          G. Payne.sup.8                              Fusarium moniliforme                                                                        6354      Illinois    C. Naidoo                                   Diplodia maydis                                                                             5139      Iowa        C. Naidoo                                   Puccinia sorghi                                                                             IL        Illinois    C. Naidoo                                   Puccinia sorghi                                                                             MI        Michigan    C. Naidoo                                   Puccinia sorghi                                                                             IL88      Illinois    C. Naidoo                                   Puccinia sorghi                                                                             VA        Virginia    C. Naidoo                                   Puccinia polyspora                                                                          TX96      Texas       C. Naidoo                                   ______________________________________                                          .sup.1 Syn. Bipolaris maydis, Drechslera maydis                                .sup.2 Dr. Charmaine Naidoo, Ciba Seeds Research, Bloomington, Illinois        USA                                                                            .sup.3 American Type Culture Collection, Rockville, Maryland USA               .sup.4 Syn. Exserohilum turcicum, Bipolaris turcica, Drechslera turcica        .sup.5 Syn. Drechslera zeicola, Bipolaris zeicola                              .sup.6 Dr. Larry Dunkle, Purdue University, West Lafayette, Indiana USA        .sup.7 Dr. Jeanne Mihail, University of MissouriColumbia, Columbia,            Missouri USA                                                                   .sup.8 Dr. Gary Payne, North Carolina State University, Raleigh, North         Carolina USA                                                             

Example 2

Isolation of the Internal Transcribed Spacer (ITS) Regions

The approximately 600 bp internal transcribed spacer region fragments were PCR amplified from 10 ng of genomic DNA isolated from H. turcicum isolates 6586, 26306 and 6402, H. maydis isolates 6921, 11534 and 24772, H. carbonum isolates 5870 and 16185, K. zeae isolates 56351, 18594 and 5125 and C. zeae-maydisisolates 5860, POS12 and Ladder 3-1 using 50 pmol of primers ITS1 (5' TCCGTAGGTGAACCTGCGG-3'; SEQ ID NO:9) and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'; SEQ ID NO:12). PCRs were performed as described in Example 4. PCR products were purified using Promega's Wizard DNA Clean-up kit (Madison, Wis.). The DNA sequences of the ITS regions were determined by the dideoxy method using the Applied Biosystems (Foster City, Calif.) automated sequencer with the primers ITS1 (SEQ ID NO:9), ITS2 (5'-GCTGCGTTCTTCATCGATGC-3'; SEQ ID NO:10), ITS4 (SEQ ID NO:12) and the M13 universal-20 (5'-GTAAAACGACGGCCAGT-3';SEQ ID NO:13) and Reverse (5'-AACAGCTATGACCATG-3'; SEQ ID NO:14) primers. The ITS primers ITS1, ITS2, ITS3, and ITS4 used are detailed in White et al. (1990; In: PCR Protocols; Eds.: Innes et al. pages 315-322). PCR products from amplifications using H. turcicum isolate 26306, H. maydis isolates 11534 and 24772, Kabatiella zeae isolate 56351, H. carbonum isolate 16185, and C. zeae-maydisisolates POS12 and Ladder 3-1 were cloned using the Invitrogen Corporation's (San Diego, Calif.) TA Cloning Kit (part no. K2000-01) using the pCRII or PCR2.1 cloning vector.

Example 3

DNA Extraction from Maize Leaves

DNA was extracted from maize leaves by using either a modified version of the Rapid DNA Extraction protocol from the MicroProbe Corporation's (Garden Grove, Calif.) IsoQuick Nucleic Acid Extraction Kit (cat# MXT-020-100) or by a bulk leaf maceration method. The Isoquick protocol was used to extract highly purified DNA from fungal-inoculated maize leaves for assay validation purposes. Typical yields using the IsoQuick kit were 5-10 μg of total DNA from 0.2 g of leaf tissue from which approximately 100 ng of total DNA were used in each PCR assay.

The bulk leaf maceration method was used to isolate DNA from several naturally infected maize leaves from the field to optimize the leaf field sampling method for high throughput analysis. In step 2 of this method, "Muller Extraction Buffer" is used. The potential concentration ranges of the ingredients of the Muller Extraction Buffer are as follows:

0-2.0 % w/v Tween-80

0-2.0 M Tris-Cl, pH 6-8

0-2.0 M NaCl

0-2 % BSA

0-2 % sodium azide

0-500 mM EDTA

0-2 % w/v tartrazin

However, in the preferred embodiment of the bulk leaf maceration method, the following recipe is used: 0.1% w/v Tween-80; 0.04 M Tris-Cl, pH 7.7; 0.15 M NaCl; 0.1% w/v BSA-Pentex fraction V; 0.01% w/v sodium azide; 200 mM EDTA. The color dye tartrazin may optionally be added as well.

Modified Rapid DNA Extraction:

Before using the kit for the first time, the entire contents of Reagent 2A (20×Dye Concentrate) were added to Reagent 2 (Extraction Matrix).

(1) Approximately 0.2 g of leaf sample were added to a 1.5 ml eppendorf tube containing 50 μl sample buffer A and 50 μl #1 lysis solution. The leaf sample was ground with a Kontes pestle.

(2) Reagent 2 (Extraction Matrix) was shaken vigorously. 350 μl of reagent 2 was added to the sample lysate.

(3) 200 μl of Reagent 3 were added (Extraction Buffer) to the sample. The sample was vortexed 20 sec.

(4) Microcentrifugation at 12,000×g for 5 min.

(5) The aqueous phase (upper layer) was transferred to a new microcentrifuge tube. This volume was typically about 200 μl.

(6) 0.1×the volume of the aqueous phase of Reagent 4 (Sodium Acetate) was transferred to the aqueous phase sample.

(7) An equal volume of isopropanol was added to the aqueous phase sample followed by vortexing.

(8) Microcentrifugation at 12,000×g for 10 min.

(9) The supernatant was discarded without disturbing the nucleic acid pellet. 0.5 ml of -20° C. 70% ethanol was added to the pellet. The tube was vortexed to mix.

(10) Microcentrifugation at 12,000×g for 5 min.

(11) The supernatant was discarded and the pellet was allowed to dry.

(12) The nucleic acid pellet was dissolved in 50 μl TE with 100 μg/ml Rnase A.

Bulk Leaf Maceration Method:

(1) Took a random sampling of an appropriate number of leaves from a population of maize plants.

(2) Placed the leaves in a Bioreba (Reinach, Switzerland) heavy duty plastic bag (cat#490100). Weighed the plant tissue, plastic bag with leaves minus the tare (weight of the plastic bag).

(3) Added an equal volume (ml) of Muller Extraction Buffer per weight (g) of leaf tissue. Macerated the tissue using a Bioreba Homex 6 homogenizer set at 70. Ground the leaves until the tissue was fibrous.

(4) Removed maceration juice (extract) from the macerated tissue/extraction buffer.

(5) Pooled the extracts from multiple bags, if used, and vortexed well. Aliquoted the extraction juice into eppendorf tubes on ice.

(6) Boiled 100 μl of the concentrated extract for 5 minutes.

(7) Placed the boiled extract on ice.

(8) Made a 1:10 dilution by adding 10 μl from the boiled, concentrated extract to 90 μl of sterile dH₂ O.

(9) Stored the diluted extracts on ice until ready to use.

Although the examples set forth herein describe using leaf tissue as the source of DNA, other plant tissue such as stem and root tissue could also be used in the above DNA extraction methods.

Example 4

Polymerase Chain Reaction Amplification

Polymerase chain reactions were performed with the GeneAmp Kit from Perkin-Elmer/Cetus (Norwalk, Conn.; part no. N808-0009) using 50 mM KCl, 2.5 mM MgCl₂, 10 mM Tris-HCl, pH8.3, containing 200 μM of each dTTP, dATP, dCTP, and dGTP, 50 pmol each primer, 2.5 units of Taq polymerase and 10 ng of genomic DNA or 1 μl of 1:10 diluted plant extract in a final volume of 50 μl. Reactions were run for 30-40 cycles of 15 s at 94° C., 15 s at 50° C.-70° C., and 45 s at 72° C. in a Perkin-Elmer/Cetus Model 9600 thermal cycler. The products were analyzed by loading 10 μl of each PCR sample on a 1.0% agarose gel and electrophoresed.

Example 5

Synthesis and Purification of Oligonucleotides

Oligonucleotides (primers) were synthesized by either Integrated DNA Technologies (Coralville, Iowa) or Midland Certified Reagent Company (Midland, Tex.).

Example 6

Selection of Species-Specific Primers

The ITS regions of H. turcicum, H. maydis, H. carbonum and C. zeae-maydiswere aligned. Separate alignments were also made for each pathogen's isolates' ITS regions. Oligonucleotide primers (Table 2) were synthesized according to Example 5 based on analysis of the aligned sequences. Primers were designed to the regions that contained the greatest differences in sequence among the fungal species. In addition, the published ribosomal gene-specific primers ITS1, ITS2, ITS3 and ITS4 (White et al., 1990; In: PCR Protocols; Eds.: Innes et al. pages 315-322) were synthesized for testing in combination with the primers specific for the ITS region. Primers specific to the ITS regions of the published Puccinia sorghi sequence (Genbank accession#L08734, SEQ ID: 8) were also synthesized.

                  TABLE 2                                                          ______________________________________                                         Primer Design for Fungal Detection                                             Primer   Primer                                                                Template Name    Primer Seguence                                               ______________________________________                                         H. turcicum                                                                             JB586   5' TGGCAATCAGTGCTCTGCTG 3'                                                     (SEQ ID NO:15)                                                H. turcicum                                                                             JB595   5' TCCGAGGTCAAAATGTGAGAG 3'                                                    (SEQ ID NO:24)                                                H. maydis                                                                               JB589   5' CCTTTTTTTTATGCAGTTGCA 3'                                                    (SEQ ID NO:18)                                                H. maydis                                                                               JB591   5' CTCCTGATACAGAGTGCAAAA 3'                                                    (SEQ ID NO:20)                                                H. maydis                                                                               JB596   5' GAGGTCAAAAGTTAAAAATCGTAA 3'                                                 (SEQ ID NO:25)                                                Helmin. spp.                                                                            JB588   5' CACCCATGTCTTTTGCGCAC 3'                                                     (SEQ ID NO:17)                                                Helmin. spp.                                                                            JB587   5' CAGTTGCAATCAGCGTCAGTA 3'                                                    (SEQ ID NO:16)                                                H. carbonum                                                                             JB592   5' CTCCTGATACAAAGCGCAAAT 3'                                                    (SEQ ID NO:21)                                                H. carbonum                                                                             JB590   5' CCTTTTTTTTTATGCAGTTACC 3'                                                   (SEQ ID NO:19)                                                H. carbonum                                                                             JB598   5' CCGAGGTCAAAAGTTAAAAATCTA 3'                                                 (SEQ ID NO:27)                                                H. carbonum                                                                             JB597   5' GGCTCCAGTTTTCAATTTTTAGAT 3'                                                 (SEQ ID NO:26)                                                K. zeae  JB616   5' TGTTGTTAAAACTACCTTGTTGC 3'                                                  (SEQ ID NO:29)                                                K. zeae  JB618   5' GTTTCTGTCGGCAGAAGTC 3'                                                      (SEQ ID NO:31)                                                K. zeae  JB615   5' TTTGGCGGGACCGCTCGG 3'                                                       (SEQ ID NO:28)                                                K. zeae  JB617   5' GAGTTAAACCAAACTCTTGTTG 3'                                                   (SEQ ID NO:30)                                                K. zeae  JB619   5' CGCCAGACGTTGATTGAATG 3'                                                     (SEQ ID NO:32)                                                C. zeae-maydis                                                                          JB593   5' GGCCTTCGGGCTCGACCT 3'                                                       (SEQ ID NO:22)                                                C. zeae-maydis                                                                          JB594   5' CGGACAGCTCAGCCGGAG 3'                                                       (SEQ ID NO:23)                                                C. zeae-maydis                                                                          JB620   5' CAACCCTTTGTGAACACAAC 3'                                                     (SEQ ID NO:33)                                                C. zeae-maydis                                                                          JB621   5' CGCTCCGAAGCGATTAATG 3'                                                      (SEQ ID NO:34)                                                C. zeae-maydis                                                                          JB622   5' TTCAAACACTGCATCTTTGCG 3'                                                    (SEQ ID NO:35)                                                C. zeae-maydis                                                                          JB623   5' AGATTTAGACGGCCGCGAC 3'                                                      (SEQ ID NO:36)                                                C. zeae-maydis                                                                          JB626   5' GAGTGAGGGCCTTCGGGC 3'                                                       (SEQ ID NO:39)                                                C. zeae-maydis                                                                          JB627   5' GCTTCGGGGGGCGACCC 3'                                                        (SEQ ID NO:40)                                                C. zeae-maydis                                                                          JB628   5' GACCGCCCGCGCTCCG 3'                                                         (SEQ ID NO:41)                                                P. sorghi                                                                               JB624   5' GTAGTCTCTATCTCAACAAC 3'                                                     (SEQ ID NO:37)                                                P. sorghi                                                                               JB625   5' GTAAACAACCACCTTTAATTAT 3'                                                   (SEQ ID NO:38)                                                18S rDNA ITS1    5' TCCGTAGGTGAACCTGCGG 31                                                      (SEQ ID NO:9)                                                 5.8S rDNA                                                                               ITS2    5' GCTGCGTTCTTCATCGATGC 3'                                                     (SEQ ID NO:10)                                                5.8S rDNA                                                                               ITS3    5' GCATCGATGAAGAACGCAGC 3'                                                     (SEQ ID NO:11)                                                25S rDNA ITS4    5' TCCTCCGCTTATTGATATGC 3'                                                     (SEQ ID NO:12)                                                ______________________________________                                          Note: Helminthosporium spp. includes H. maydis, H. turcicum and H.             carbonum.                                                                

Example 7

Determination of Primer Specificity to Purified Fungal Genomic DNA

PCRs were performed according to Example 4 using different primer combinations (Table 3) in an attempt to amplify a single species-specific fragment. Species-specific PCR amplification products were produced from primers designed from the ITS region between the 18S and 25S ribosomal DNA subunits of each fungal strain of interest.

                  TABLE 3                                                          ______________________________________                                         ITS-Derived Diagnostic PCR Primers                                                                                Approximate                                                                    size of                                     Source of                          amplified                                   template DNA                                                                              5'Primer    3'Primer    fragment                                    ______________________________________                                         H. turcicum                                                                               JB586       JB595       485bp                                                  (SEQ ID NO:15)                                                                             (SEQ ID NO:24)                                          H. maydis  JB589       JB591       346bp                                                  (SEQ ID NO:18)                                                                             (SEQ ID NO:20)                                          H. maydis  JB589       JB596       397bp                                                  (SEQ ID NO:18)                                                                             (SEQ ID NO:25)                                          H. maydis  JB588       JB596       463bp                                                  (SEQ ID NO:17)                                                                             (SEQ ID NO:25)                                          H. maydis  JB588       JB591       413bp                                                  (SEQ ID NO:17)                                                                             (SEQ ID NO:20)                                          H. maydis  JB587       JB596       331bp                                                  (SEQ ID NO:16)                                                                             (SEQ ID NO:25)                                          H. maydis  JB587       JB591       333bp                                                  (SEQ ID NO:16)                                                                             (SEQ ID NO:20)                                          H. maydis  JB588       JB598       465bp                                                  (SEQ ID NO:17)                                                                             (SEQ ID NO:27)                                          H. maydis  JB587       JB598       375bp                                                  (SEQ ID NO:16)                                                                             (SEQ ID NO:27)                                          H. carbonum                                                                               JB590       JB598       398bp                                                  (SEQ ID NO:19)                                                                             (SEQ ID NO:27)                                          H. carbonum                                                                               JB590       JB592       346bp                                                  (SEQ ID NO:19)                                                                             (SEQ ID NO:21)                                          H. carb./H. maydis                                                                        JB588)      JB598       465bp                                                  (SEQ ID NO:17)                                                                             (SEQ ID NO:27)                                          H. carb./H. maydis                                                                        JB587       JB598       384bp                                                  (SEQ ID NO:16)                                                                             (SEQ ID NO:27)                                          K. zeae    JB616       JB618       455bp                                                  (SEQ ID NO:29)                                                                             (SEQ ID NO:31)                                          K. zeae    JB615       ITS4        508bp                                                  (SEQ ID NO:28)                                                                             (SEQ ID NO:12)                                          K. zeae    JB616       ITS4        531bp                                                  (SEQ ID NO:29)                                                                             (SEQ ID NO:12)                                          K. zeae    JB617       ITS4        443bp                                                  (SEQ ID NO:30)                                                                             (SEQ ID NO:12)                                          K. zeae    JB615       JB618       433bp                                                  (SEQ ID NO:28)                                                                             (SEQ ID NO:31)                                          K. zeae    JB617       JB618       366bp                                                  (SEQ ID NO:30)                                                                             (SEQ ID NO:31)                                          K. zeae    JB615       JB619       402bp                                                  (SEQ ID NO:28)                                                                             (SEQ ID NO:32)                                          C. zeae-maydis                                                                            JB593       JB594       380bp                                                  (SEQ ID NO:22)                                                                             (SEQ ID NO:23)                                          C. zeae-maydis                                                                            JB620       JB621       393bp                                                  (SEQ ID NO:33)                                                                             (SEQ ID NO:34)                                          C. zeae-maydis                                                                            JB620       JB623       420bp                                                  (SEQ ID NO:33)                                                                             (SEQ ID NO:36)                                          C. zeae-maydis                                                                            JB622       JB621       320bp                                                  (SEQ ID NO:35)                                                                             (SEQ ID NO:34)                                          C. zeae-maydis                                                                            JB593       JB621       415bp                                                  (SEQ ID NO:22)                                                                             (SEQ ID NO:34)                                          C. zeae-maydis                                                                            JB622       JB594       285bp                                                  (SEQ ID NO:35)                                                                             (SEQ ID NO:23)                                          C. zeae-maydis                                                                            JB593       JB623       442bp                                                  (SEQ ID NO:22)                                                                             (SEQ ID NO:36)                                          C. zeae-maydis                                                                            JB626       JB628       427bp                                                  (SEQ ID NO:39)                                                                             (SEQ ID NO:41)                                          C. zeae-maydis                                                                            JB593       ITS4        558bp                                                  (SEQ ID NO:22)                                                                             (SEQ ID NO:12)                                          P. sorghi  JB624       JB625       409bp                                                  (SEQ ID NO:37)                                                                             (SEQ ID NO:38)                                          P. sorghi/Helm.spp.                                                                       JB587       ITS4        434bp                                                  (SEQ ID NO:16)                                                                             (SEQ ID NO:12)                                          P. sorghi/Helm.spp.                                                                       JB588       ITS4        517bp                                                  (SEQ ID NO:17)                                                                             (SEQ ID NO:12)                                          ______________________________________                                          Note: Helminthosporium spp. includes H. maydis, H. turcicum and H.             carbonum.                                                                

Example 8

Determination of Primer Specificity to Plant Tissue Infected with Fungi and Cross-Reactivity with Other Maize Fungal Pathogens

Total genomic DNA was isolated as described in Example 3 from healthy maize leaves and from maize leaves inoculated with either H. turcicum, H. maydis, H. carbonum, K. zeae, C. zeae-maydisor P. sorghi. PCRs were performed as described in Example 4 testing the primer combinations listed in Example 7 against DNA from the maize leaves. Purified fungal genomic DNAs were obtained as described in Example 1 and PCR assayed as described in Example 4 using the species-specific primers. Other fungal DNA species and isolates were tested for the species-specific primers ability to cross-react with them.

The H. turcicum-specific primers JB586 (SEQ ID NO:15) and JB595 (SEQ ID NO:24) amplified a 485 bp fragment from DNA from all of the isolates of H. turcicum listed in Table 1 and from H. turcicum-infected maize leaf tissue. The primer set did not amplify a diagnostic fragment from healthy maize leaf tissue nor from purified genomic DNA from H. maydis, H. carbonum, K. zeae, C. zeae-maydisand P. sorghi. The primers also did not amplify a diagnostic fragment from purified genomic DNA isolated from the common maize pathogens F. monililforme, M. phaseolina, A. flavus nor D. maydis.

Similar diagnostic results were obtained with the H. maydis-specific primers JB589 (SEQ ID NO:18) and JB591 (SEQ ID NO:20). The primers amplified an approximately 346 bp fragment from H. maydis-infected maize tissue, as well as from purified genomic DNA isolated from all of the H. maydis isolates listed in Table 1. The primer combination JB589 and JB591 did not amplify any fragments from healthy maize tissue, nor from DNA from any of the following maize pathogens: H. turcicum, H. carbonum, K. zeae, C. zeae-maydis, P. sorghi, F. moniliforme, M. phaseolina, A. flavus and D. maydis.

The primer combination JB590 (SEQ ID NO:19) and JB598 (SEQ ID NO:27) amplified a 398 bp fragment from DNA from all of the H. carbonum isolates listed in Table 1 and from maize leaves infected with H. carbonum. The primer combination JB590 and JB598 did not amplify any fragments from healthy maize tissue, nor from DNA from any of the following maize pathogens: H. turcicum, H. maydis, K. zeae, C. zeae-maydis, P. sorghi, F. moniliforme, M. phaseolina, A. flavus and D. maydis.

The K. zeae-specific primers JB616 (SEQ ID NO:29) and JB618 (SEQ ID NO:31) amplified a 455 bp fragment from DNA from all of the isolates of K. zeae isolates listed in Table 1 and from K. zeae-infected maize leaf tissue. The primer set did not amplify a diagnostic fragment from healthy maize leaf tissue nor from purified genomic DNA from H. maydis, H. carbonum, H. turcicum, C. zeae-maydisand P. sorghi. The primers also did not amplify a diagnostic fragment from purified genomic DNA isolated from the common maize pathogens F. monililfonne, M. phaseolina, A. flavus nor D. maydis.

The primer combination JB593 (SEQ ID NO:22) and JB621 (SEQ ID NO:34) amplified a 415 bp fragment from DNA from all of the C. zeae-maydisisolates listed in Table 1 and from maize leaves infected with C. zeae-maydis. The primer combination JB593 and JB621 did not amplify any fragments from healthy maize tissue, nor from DNA from any of the following maize pathogens: H. turcicum, H. maydis, K. zeae, H. carbonum, P. sorghi, F. moniliforme, M. phaseolina, A. flavus and D. maydis.

The primer combination JB624 (SEQ ID NO:37) and JB625 (SEQ ID NO:38) amplified a 409 bp fragment from all of the P. sorghi isolates listed in Table 1 and from P. sorghi-infected maize leaf tissue. The primers did not amplify from P. polyspora, H. turcicum, H. maydis, K. zeae, H. carbonum, F. moniliforme, M. phaseolina, A. flavus and D. maydis. The primers also did not amplify from healthy maize tissue.

Primers JB587 (SEQ ID NO:16) and ITS4 (SEQ ID NO:12) amplified a 434 bp fragment from P. sorghi, H. turcicum, H. maydis and H. carbonum but not from the other following maize pathogens: K. zeae, F. moniliforme, M. phaseolina, A. flavus and D. maydis. The primers also amplified a 434 bp fragment from maize infected with P. sorghi, H. turcicum, H. maydis and H. carbonum but did not amplify any fragments from healthy maize tissue.

While the present invention has been described with reference to specific embodiments thereof, it will be appreciated that numerous variations, modifications, and further embodiments are possible, and accordingly, all such variations, modifications and embodiments are to be regarded as being within the scope of the present invention.

DEPOSITS

The following deposits were made on Nov. 6, 1996, at Agricultural Research Service, Patent Culture Collection (NRRL), Northern Regional Research Center, 1815 North University Street, Peoria, Ill. 61604, U.S.A.:

1. E. coli DH5α (pCRCZLAD3-1(4-3); SEQ ID NO:1): Accession No. NRRL B-21645.

2. E. coli DH5α (pCRCZMPOS12(2-1); SEQ ID NO:2): Accession No. NRRL B-21641.

3. E. coli DH5α (pCRKZ56351(5-1); SEQ ID NO:3): Accession No. NRRLB-21646.

4. E. coli DH5α (pCRHMAY24772(2-1); SEQ ID NO:4): Accession No. NRRL B-21642.

5. E. coli DH5α (pCRHMAY11534(4-1); SEQ ID NO:5): Accession No. NRRL B-21644.

6. E. coli DH5α (pCRHTUR26306(3-1); SEQ ID NO:6): Accession No. NRRL B-21643.

7. E. coli DH5α (pCRHCAR16185(5-2); SEQ ID NO:7): Accession No. NRRL B-21647.

    __________________________________________________________________________     #             SEQUENCE LISTING                                                 - (1) GENERAL INFORMATION:                                                     -    (iii) NUMBER OF SEQUENCES: 41                                             - (2) INFORMATION FOR SEQ ID NO:1:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 535 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                    #zeae-maydis) STRAIN: Cercospora                                               #Ladder 3-1C) INDIVIDUAL ISOLATE:                                              -    (vii) IMMEDIATE SOURCE:                                                             (B) CLONE: pCRCZLAD3-1(4-3 - #)                                      -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 1..30                                                  #/note= "3' end of small subunit                                                              rRNA gene - #"                                                  -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 31..175                                                #/note= "ITS 1"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 176..332                                               #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 333..478                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 479..535                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:                                  - TCCGTAGGTG AACCTGCGGA GGGATCATTA CTGAGTGAGG GCCTTCGGGC TC - #GACCTCCA          60                                                                           - ACCCTTTGTG AACACAACTT GTTGCTTCGG GGGCGACCCT GCCGTTCCGA CG - #GCGAGCGC         120                                                                           - CCCCGGAGGC CTTCAAACAC GCATCTTTGC GTCGGAGTTT AAGTAAATTA AA - #CAAAACTT         180                                                                           - TCAACAACGG ATCTCTTGGT TCTGGCATCG ATGAAGAACG CAGCGAAATG CG - #ATAAGTAA         240                                                                           - TGTGAATTGC AGAATTCAGT GAATCATCGA ATCTTTGAAC GCATATTGCG CC - #CTTTGGTA         300                                                                           - TTCCGAAGGG CATGCCTGTT CGAGCGTCAT TTCACCACTC AAGCCTAGCT TG - #GTACTGGG         360                                                                           - CGCCGCGGTG TTCCGCGCGC CTTAAAGTCT CCGGCTGAGC TGTCCGTCTC TA - #AGCGTTGT         420                                                                           - GATTTCATTA ATCGCTTCGG AGCGCGGGCG GTCGCGGCCG TTAAATCTTT CA - #CAAGGTTG         480                                                                           - ACCTCGGATC AGGTAGGGAT ACCCGCTGAA CTTAAGCATA TCAATAAGCG GA - #GGA              535                                                                           - (2) INFORMATION FOR SEQ ID NO:2:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 536 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                    #zeae-maydis) STRAIN: Cercospora                                               #POS 12   (C) INDIVIDUAL ISOLATE:                                              -    (vii) IMMEDIATE SOURCE:                                                             (B) CLONE: pCRCZMPOS12(2-1 - #)                                      -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 1..30                                                  #/note= "3' end of small subunit                                                              rRNA gene - #"                                                  -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 31..176                                                #/note= "ITS 1"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 177..333                                               #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 334..479                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 480..536                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:                                  - TCCGTAGGTG AACCTGCGGA GGGATCATTA CTGAGTGAGG GCCTTCGGGC TC - #GACCTCCA          60                                                                           - ACCCTTTGTG AACACAACTT GTTGCTTCGG GGGCGACCCT GCCGTTCCGA CG - #GCGAGCGC         120                                                                           - CCCCGGAGGC CTTCAAACAC TGCATCTTTG CGTCGGAGTT TAAGTAAATT AA - #ACAAAACT         180                                                                           - TTCAACAACG GATCTCTTGG TTCTGGCATC GATGAAGAAC GCAGCGAAAT GC - #GATAAGTA         240                                                                           - ATGTGAATTG CAGAATTCAG TGAATCATCG AATCTTTGAA CGCATATTGC GC - #CCTTTGGT         300                                                                           - ATTCCGAAGG GCATGCCTGT TCGAGCGTCA TTTCACCACT CAAGCCTAGC TT - #GGTATTGG         360                                                                           - GCGCCGCGGT GTTCCGCGCG CCTTAAAGTC TCCGGCTGAG CTGTCCGTCT CT - #AAGCGTTG         420                                                                           - TGATTTCATT AATCGCTTCG GAGCGCGGGC GGTCGCGGCC GTTAAATCTT TC - #ACAAGGTT         480                                                                           - GACCTCGGAT CAGGTAGGGA TACCCGCTGT ACTTAAGCAT ATCAATAAGC GG - #AGGA             536                                                                           - (2) INFORMATION FOR SEQ ID NO:3:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 597 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                    #zeae     (B) STRAIN: Kabatiella                                               #56351    (C) INDIVIDUAL ISOLATE:                                              -    (vii) IMMEDIATE SOURCE:                                                             (B) CLONE: pCRKZ56351(5-1)                                           -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 1..30                                                  #/note= "3' end of small subunit                                                              rRNA gene - #"                                                  -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 31..217                                                #/note= "ITS 1"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 218..373                                               #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 374..540                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 541..597                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:                                  - TCCGTAGGTG AACCTGCGGA AGGATCATTA AAGAGTAAGG GTGCCCAGCG CC - #CGACCTCC          60                                                                           - AACCCTTTGT TGTTAAAACT ACCTTGTTGC TTTGGCGGGA CCGCTCGGTC CC - #CGAGCCGC         120                                                                           - CGGGGGGATC CGTCCCCCAT GGCGAGCGCC CGCCGGAGTT AAACCAAACT CT - #TGTTGAAC         180                                                                           - AAACCGGTCG TCTGAGTTAA AATTTTGAAT AAATCAAAAC TTTCAACAAC GG - #ATCTCTTG         240                                                                           - GTTCTCGCAT CGATGAAGAA CGCAGCGAAA TGCGATAAGT AATGTGAATT GC - #AGAATTCA         300                                                                           - GTGAATCATC GAATCTTTGA ACGCACATTG CGCCCCTTGG TATTCCGAGG GG - #CATGCCTG         360                                                                           - TTCGAGCGTC ATTACACCAC TCAAGCTCTG CTTGGTATTG GGCGTCCGTC CT - #TTCGGGGG         420                                                                           - CGCGCCTCAA ACACCTCGGC GAGGCCTCAC CGGCTTCAGG CGTAGTAGAA TT - #CATTCAAT         480                                                                           - CAACGTCTGG CGAAACCGGA GGGGACTTCT GCCGACAGAA ACCTTTTATA TT - #TTCTAGGT         540                                                                           - TGACCTCGGA TCAGGTAGGG ATACCCGCTG AACTTAAGCA TATCAATAAG CG - #GAGGA            597                                                                           - (2) INFORMATION FOR SEQ ID NO:4:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 588 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                              (B) STRAIN: Helminthospori - #um maydis                              #24772    (C) INDIVIDUAL ISOLATE:                                              -    (vii) IMMEDIATE SOURCE:                                                             (B) CLONE: pCRHMAY24772(2- - #1)                                     -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 1..30                                                  #/note= "3' end of small subunit                                                              rRNA gene - #"                                                  -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 31..200                                                #/note= "ITS 1"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 201..358                                               #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 359..531                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 532..588                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:                                  - TCCGTAGGTG AACCTGCGGA GGGATCATTA CACAACAAAA TATGAAGGCC TG - #GCTTTGCG          60                                                                           - GCCGGCTGAA ATATTTTTTT CACCCATGTC TTTTGCGCAC TTGTTGTTTC CT - #GGGCGGGT         120                                                                           - TCGCCCGCCA CCAGGACCAA ACCCTAAACC TTTTTTTTAT GCAGTTGCAW TC - #AGCGTCAG         180                                                                           - TATAAACAAT GTAATTATTA CAACTTTCAA CAACGGATCT CTTGGTTCTG GC - #ATCGATGA         240                                                                           - AGAACGCAGC GAAATGCGAT ACGTAGTGTG AATTGCAGAA TTCAGTGAAT CA - #TCGAATCT         300                                                                           - TTGAACGCAC ATTGCGCCCT TTGGTATTCC AAAGGGCATG CCTGTTCGAG CG - #TCATTTGT         360                                                                           - ACCCTCAAGC TTTGCTTGGT GTTGGGCGTT TTTGTCTCCC TCTTTGCTGG GA - #GACTCGCC         420                                                                           - TTAAAACGAW TGGCAGCCGG CCTACTGGTT TCGGAGCGCA GCACATATTT TG - #CACTCTGT         480                                                                           - ATCAGGAGAA AAGGACGGTA ATCCATCAAG ACTCTTACGA TTTTTAACTT TT - #GACCTCGG         540                                                                           #               588CGCT GAACTTAAGC ATATCAATAA GCGGAGGA                         - (2) INFORMATION FOR SEQ ID NO:5:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 588 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                              (B) STRAIN: Helminthospori - #um maydis                              #11534    (C) INDIVIDUAL ISOLATE:                                              -    (vii) IMMEDIATE SOURCE:                                                             (B) CLONE: pCRHMAY11534(4- - #1)                                     -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 1..30                                                  #/note= "3' end of small subunit                                                              rRNA gene - #"                                                  -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 31..200                                                #/note= "ITS 1"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 201..358                                               #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 359..531                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 532..588                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:                                  - TCCGTAGGTG AACCTGCGGA GGGATCATTA CACAACAAAA TATGAAGGCC TG - #GCTTTGCG          60                                                                           - GCCGGCTGAA ATATTTTTTT CACCCATGTC TTTTGCGCAC TTGTTGTTTC CT - #GGGCGGGT         120                                                                           - TCGCCCGCCA CCAGGACCAA ACCATAAACC TTTTTTTTAT GCAGTTGCAA TC - #AGCGTCAG         180                                                                           - TATAAACAAT GTAATTATTA CAACTTTCAA CAACGGATCT CTTGGTTCTG GC - #ATCGATGA         240                                                                           - AGAACGCAGC GAAATGCGAT ACGTAGTGTG AATTGCAGAA TTCAGTGAAT CA - #TCGAATCT         300                                                                           - TTGAACGCAC ATTGCGCCCT TTGGTATTCC AAAGGGCATG CCTGTTCGAG CG - #TCATTTGT         360                                                                           - ACCCTCAAGC TTTGCTTGGT GTTGGGCGTT TTTGTCTCCC TCTTTGCTGG GA - #GACTCGCC         420                                                                           - TTAAAACGAT TGGCAGCCGG CCTACTGGTT TCGGAGCGCA GCACATATTT TG - #CACTCTGT         480                                                                           - ATCAGGAGAA AAGGACGGTA ATCCATCAAG ACTCTTACGA TTTTTAACTT TT - #GACCTCGG         540                                                                           #               588CGCT GAACTTAAGC ATATCAATAA GCGGAGGA                         - (2) INFORMATION FOR SEQ ID NO:6:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 580 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                              (B) STRAIN: Helminthospori - #um turcicum                            #26306    (C) INDIVIDUAL ISOLATE:                                              -    (vii) IMMEDIATE SOURCE:                                                             (B) CLONE: pCRHTUR26306(3- - #1)                                     -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 1..30                                                  #/note= "3' end of small subunit                                                              rRNA gene - #"                                                  -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 31..199                                                #/note= "ITS 1"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 200..356                                               #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 357..523                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 524..580                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:                                  - TCCGTAGGTG AACCTGCGGA GGGATCATTA CACAAAGATA TGAAGGTAGG GT - #ACTGGCAA          60                                                                           - CAGTGCTCTG CTGAAATATT TTCACCCATG TCTTTTGCGC ACTTTTTGTT TC - #CTGGGCGA         120                                                                           - GTTTGCTCGC CACCAGGACC CCCATATGAA CCTTTTTTGT TTTTGCACTC AG - #CGTCAGTA         180                                                                           - CAATAATTTA ATCTATTAAA ACTTTCAACA ACGGATCTCT TGGTTCTGGC AT - #CGATGAAG         240                                                                           - AACGCAGCGA AATGCGATAC GTAGTGTGAA TTGCAGAATT CAGTGAATCA TC - #GAATCTTT         300                                                                           - GAACGCACAT TGCGCCCTTT GGTATTCCAA AGGGCATGCC TGTTCGAGCG TC - #ATTTGTAC         360                                                                           - CCTCAAGCTT TGCTTGGTGT TGGGCGTCTT ATTGTCTCTC CGTCTCGGGG AG - #ACTCGCCT         420                                                                           - TAAAACAATT GGCAGCCGGC CTACTGGTTT CGGAGCGCAG CACAAATTTG CG - #CTTGCAAT         480                                                                           - CAGCCAAGGG CGGCATCCAT GAAGCCTTTT TTCTCTCACA TTTTGACCTC GG - #ATCAGGTA         540                                                                           #   580            TTAA GCATATCAAT AAGCGGAGGA                                  - (2) INFORMATION FOR SEQ ID NO:7:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 587 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                              (B) STRAIN: Helminthospori - #um carbonum                            #16185    (C) INDIVIDUAL ISOLATE:                                              -    (vii) IMMEDIATE SOURCE:                                                             (B) CLONE: pCRHCAR16185(5- - #2)                                     -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 1..30                                                  #/note= "3' end of small subunit                                                              rRNA gene - #"                                                  -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 31..202                                                #/note= "ITS 1"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 203..360                                               #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 361..530                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 531..587                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:                                  - TCCGTAGGTG AACCTGCGGA GGGATCATTA CACAACAAAA TATGAAGGCC CT - #GGCTTCGC          60                                                                           - GGCCGGCTGA AATATTTTTT CACCCATGTC TTTTGCGCAC TTGTTGTTTC CT - #GGGCGGGT         120                                                                           - TTGCCCGCCA CCAGGACCAA ACCATAAACC TTTTTTTTTA TGCAGTTACC AT - #CAGCGTCA         180                                                                           - GTAAAAACAA TGTAATTAAT TACAACTTTC AACAACGGAT CTCTTGGTTC TG - #GCATCGAT         240                                                                           - GAAGAACGCA GCGAAATGCG ATACGTAGTG TGAATTGCAG AATTCAGTGA AT - #CATCGAAT         300                                                                           - CTTTGAACGC ACATTGCGCC CTTTGGTATT CCAAAGGGCA TGCCTGTTCG AG - #CGTCATTT         360                                                                           - GTACCTTCAA GCTTTGCTTG GTGTTGGGCG TTTTTGTCTC CCTCTTTCTG GG - #AGACTCGC         420                                                                           - CTTAAAACGA TTGGCAGCCG GCCTACTGGT TTCGGAGCGC AGCACATAAT TT - #GCGCTTTG         480                                                                           - TATCAGGAGA AAAGGACGGT AATCCATCAA GACTCTAGAT TTTTAACTTT TG - #ACCTCGGA         540                                                                           #               587GCTG AACTTAAGCA TATCAATAAG CGGAGGA                          - (2) INFORMATION FOR SEQ ID NO:8:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 458 base                                                           (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (vi) ORIGINAL SOURCE:                                                              (B) STRAIN: Puccinia so - #rghi                                      #SZZI11   (C) INDIVIDUAL ISOLATE:                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1..45                                                  #/note= "partial ITS 1"ORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 46..201                                                #/note= "5.8S rRNA gene"RMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 202..441                                               #/note= "ITS 2"THER INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #RNA                                               (B) LOCATION: 442..458                                               #/note= "5' end of large subunit                                                              rRNA gene - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:                                  - ACACAAGTTT AAAAGAATGT AAACAACCAC CTTTAATTAT AAAAATAACT TT - #TAACAATG          60                                                                           - GATCTCTAGG CTCTCACATC GATGAAGAAC ACAGTGAAAT GTGATAAGTA AT - #GTGAATTG         120                                                                           - CAGAATTCAG TGAATCATCG AATCTTTGAA CGCATCTTGC GCCTTTTGGT AT - #TCCAAAAG         180                                                                           - GCACACCTGT TTGAGTGTCA TGAAACCCTC TCACAAAATA AATAATTTTT AT - #TATGATTT         240                                                                           - TTGTGGATGT TGAGTGCTGC TGTGTTACAC ATAGCTCACT TTAAATGTAT AA - #GTCATCTT         300                                                                           - CTTTATATAG CAAAAAAGAA GAGATGGATT GACTTGATGT GTAATAATTT TT - #TTTCATCA         360                                                                           - CATTGAGGAA AGTAGCAATA CTTGCCATCT TTATATTATT TTGTTGTTGA GA - #TAGAGACT         420                                                                           #    458           AAAA TTTAAGACCT CAAATCAG                                    - (2) INFORMATION FOR SEQ ID NO:9:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 19 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer ITS1"SCRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:                                  # 19               CGG                                                         - (2) INFORMATION FOR SEQ ID NO:10:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer ITS2"SCRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:                                 # 20               ATGC                                                        - (2) INFORMATION FOR SEQ ID NO:11:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer ITS3"SCRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:                                 # 20               CAGC                                                        - (2) INFORMATION FOR SEQ ID NO:12:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer ITS4"SCRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:                                 # 20               ATGC                                                        - (2) INFORMATION FOR SEQ ID NO:13:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 17 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "M13 universal-20 primer"desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:                                 #   17             T                                                           - (2) INFORMATION FOR SEQ ID NO:14:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 16 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "Reverse primer used in /desc                                                              Example 2 - #"                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:                                 #    16                                                                        - (2) INFORMATION FOR SEQ ID NO:15:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB586"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:                                 # 20               GCTG                                                        - (2) INFORMATION FOR SEQ ID NO:16:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 21 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB587"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:16:                                 #21                CAGT A                                                      - (2) INFORMATION FOR SEQ ID NO:17:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB588"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:17:                                 # 20               GCAC                                                        - (2) INFORMATION FOR SEQ ID NO:18:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 21 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB589"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:18:                                 #21                TTGC A                                                      - (2) INFORMATION FOR SEQ ID NO:19:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 22 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB590"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:19:                                 #                 22TTA CC                                                     - (2) INFORMATION FOR SEQ ID NO:20:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 21 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB591"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:20:                                 #21                CAAA A                                                      - (2) INFORMATION FOR SEQ ID NO:21:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 21 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB592"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:21:                                 #21                CAAA T                                                      - (2) INFORMATION FOR SEQ ID NO:22:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 18 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB593"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:22:                                 #  18              CT                                                          - (2) INFORMATION FOR SEQ ID NO:23:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 18 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB594"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:23:                                 #  18              AG                                                          - (2) INFORMATION FOR SEQ ID NO:24:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 21 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB595"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:24:                                 #21                GAGA G                                                      - (2) INFORMATION FOR SEQ ID NO:25:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 24 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB596"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:25:                                 #                24AATC GTAA                                                   - (2) INFORMATION FOR SEQ ID NO:26:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 24 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB597"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:26:                                 #                24TTTT AGAT                                                   - (2) INFORMATION FOR SEQ ID NO:27:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 24 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB598"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:27:                                 #                24AAAA TCTA                                                   - (2) INFORMATION FOR SEQ ID NO:28:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 18 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB615"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:28:                                 #  18              GG                                                          - (2) INFORMATION FOR SEQ ID NO:29:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 23 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB616"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:29:                                 #                23TTGT TGC                                                    - (2) INFORMATION FOR SEQ ID NO:30:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 22 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB617"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:30:                                 #                 22TGT TG                                                     - (2) INFORMATION FOR SEQ ID NO:31:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 19 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB618"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:31:                                 # 19               GTC                                                         - (2) INFORMATION FOR SEQ ID NO:32:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB619"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:32:                                 # 20               AATG                                                        - (2) INFORMATION FOR SEQ ID NO:33:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB620"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:33:                                 # 20               CAAC                                                        - (2) INFORMATION FOR SEQ ID NO:34:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 19 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB621"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:34:                                 # 19               ATG                                                         - (2) INFORMATION FOR SEQ ID NO:35:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 21 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB622"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:35:                                 #21                TTGC G                                                      - (2) INFORMATION FOR SEQ ID NO:36:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 19 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB623"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:36:                                 # 19               GAC                                                         - (2) INFORMATION FOR SEQ ID NO:37:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 20 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB624"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:37:                                 # 20               CAAC                                                        - (2) INFORMATION FOR SEQ ID NO:38:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 22 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB625"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:38:                                 #                 22ATT AT                                                     - (2) INFORMATION FOR SEQ ID NO:39:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 18 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB626"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:39:                                 #  18              GC                                                          - (2) INFORMATION FOR SEQ ID NO:40:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 17 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB627"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:40:                                 #   17             C                                                           - (2) INFORMATION FOR SEQ ID NO:41:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 16 base                                                            (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: other nucleic acid                                   #= "primer JB628"CRIPTION: /desc                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:41:                                 #    16                                                                        __________________________________________________________________________ 

What is claimed is:
 1. A DNA extraction buffer, comprising:(a) approximately 0.1% w/v Tween-80; (b) approximately 0.04 M Tris-Cl, pH 6-8; (c) 0.15-2.0 M NaCl; (d) approximately 0.1% BSA; (e) approximately 0.01% sodium azide; and (f) 180-500 mM EDTA.
 2. The extraction buffer of claim 1, comprising: 0.1% w/v Tween-80; 0.04 M Tris-Cl, pH 7.7; 0.15 M NaCl; 0.1% w/v BSA-Pentex fraction V; 0.01% w/v sodium azide; and 200 mM EDTA.
 3. The extraction buffer of claim 1, further comprising 0-2% w/v tartrazin.
 4. A method for preparing an extract of DNA from tissue, comprising the steps of:(a) taking a plurality of random tissue samples from an organism population; (b) adding the extraction buffer of claim 1 to the tissue samples; (c) macerating the tissue samples and extraction buffer to form an extract; and (d) removing the extract from the macerated tissue and buffer.
 5. The method of claim 4, wherein the organism population is a plant population.
 6. The method of claim 5, wherein the tissue samples are selected from leaves, stems, and roots.
 7. The method of claim 4, wherein the extraction buffer comprises 0.1% w/v Tween-80; 0.04 M Tris-Cl, pH 7.7; 0.15 M NaCl; 0.1% w/v BSA-Pentex fraction V; 0.01% w/v sodium azide; and 200 mM EDTA.
 8. A method for performing PCR analysis on DNA extracted from tissue, comprising the steps of:(a) taking a plurality of random tissue samples from an organism population; (b) adding the extraction buffer of claim 1 to the tissue samples; (c) macerating the tissue samples and extraction buffer to form an extract; (d) removing the extract from the macerated tissue and buffer; and (e) performing PCR analysis on the extract.
 9. The method of claim 8, further comprising the step of boiling the extract after removing it from the macerated tissue and buffer.
 10. The method of claim 9, further comprising the step of diluting the extract.
 11. The method of claim 10, wherein the organism population is a plant population.
 12. The method of claim 11, wherein the tissue samples are selected from leaves, stems, and roots.
 13. The method of claim 8, wherein the extraction buffer comprises 0.1% w/v Tween-80; 0.04 M Tris-Cl, pH 7.7; 0.15 M NaCl; 0.1% w/v BSA-Pentex fraction V; 0.01% w/v sodium azide; and 200 mM EDTA.
 14. The DNA extraction buffer of claim 1, comprising 0.1% w/v Tween-80.
 15. The DNA extraction buffer of claim 1, comprising 0.04 M Tris-Cl, pH 6-8.
 16. The DNA extraction buffer of claim 1, comprising 0.15 M NaCl.
 17. The DNA extraction buffer of claim 1, comprising 0.1% BSA.
 18. The DNA extraction buffer of claim 1, comprising 0.01% sodium azide.
 19. The DNA extraction buffer of claim 1, comprising 200 mM EDTA. 